From patchwork Mon Oct 19 08:57:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dylan Hung X-Patchwork-Id: 11843847 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEC70C43457 for ; Mon, 19 Oct 2020 08:57:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 61DB920874 for ; Mon, 19 Oct 2020 08:57:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729914AbgJSI5u (ORCPT ); Mon, 19 Oct 2020 04:57:50 -0400 Received: from twspam01.aspeedtech.com ([211.20.114.71]:65342 "EHLO twspam01.aspeedtech.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729840AbgJSI5u (ORCPT ); Mon, 19 Oct 2020 04:57:50 -0400 Received: from mail.aspeedtech.com ([192.168.0.24]) by twspam01.aspeedtech.com with ESMTP id 09J8so81046772; Mon, 19 Oct 2020 16:54:50 +0800 (GMT-8) (envelope-from dylan_hung@aspeedtech.com) Received: from localhost.localdomain (192.168.10.9) by TWMBX02.aspeed.com (192.168.0.24) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 19 Oct 2020 16:57:27 +0800 From: Dylan Hung To: , , , , , , CC: , Joel Stanley Subject: [PATCH 1/4] ftgmac100: Fix race issue on TX descriptor[0] Date: Mon, 19 Oct 2020 16:57:14 +0800 Message-ID: <20201019085717.32413-2-dylan_hung@aspeedtech.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201019085717.32413-1-dylan_hung@aspeedtech.com> References: <20201019085717.32413-1-dylan_hung@aspeedtech.com> MIME-Version: 1.0 X-Originating-IP: [192.168.10.9] X-ClientProxiedBy: TWMBX02.aspeed.com (192.168.0.24) To TWMBX02.aspeed.com (192.168.0.24) X-DNSRBL: X-MAIL: twspam01.aspeedtech.com 09J8so81046772 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org These rules must be followed when accessing the TX descriptor: 1. A TX descriptor is "cleanable" only when its value is non-zero and the owner bit is set to "software" 2. A TX descriptor is "writable" only when its value is zero regardless the edotr mask. Fixes: 52c0cae87465 ("ftgmac100: Remove tx descriptor accessors") Signed-off-by: Dylan Hung Signed-off-by: Joel Stanley --- drivers/net/ethernet/faraday/ftgmac100.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c index 00024dd41147..7cacbe4aecb7 100644 --- a/drivers/net/ethernet/faraday/ftgmac100.c +++ b/drivers/net/ethernet/faraday/ftgmac100.c @@ -647,6 +647,9 @@ static bool ftgmac100_tx_complete_packet(struct ftgmac100 *priv) if (ctl_stat & FTGMAC100_TXDES0_TXDMA_OWN) return false; + if ((ctl_stat & ~(priv->txdes0_edotr_mask)) == 0) + return false; + skb = priv->tx_skbs[pointer]; netdev->stats.tx_packets++; netdev->stats.tx_bytes += skb->len; @@ -756,6 +759,9 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb, pointer = priv->tx_pointer; txdes = first = &priv->txdes[pointer]; + if (le32_to_cpu(txdes->txdes0) & ~priv->txdes0_edotr_mask) + goto drop; + /* Setup it up with the packet head. Don't write the head to the * ring just yet */ @@ -787,6 +793,10 @@ static netdev_tx_t ftgmac100_hard_start_xmit(struct sk_buff *skb, /* Setup descriptor */ priv->tx_skbs[pointer] = skb; txdes = &priv->txdes[pointer]; + + if (le32_to_cpu(txdes->txdes0) & ~priv->txdes0_edotr_mask) + goto dma_err; + ctl_stat = ftgmac100_base_tx_ctlstat(priv, pointer); ctl_stat |= FTGMAC100_TXDES0_TXDMA_OWN; ctl_stat |= FTGMAC100_TXDES0_TXBUF_SIZE(len);